scholarly journals Temperature Dependent Current Transport Mechanism of Photopolymer Based Al/NOA60/p-Si MPS Device

2021 ◽  
Author(s):  
Şadan Özden ◽  
Nejmettin Avcı ◽  
Osman Pakma ◽  
Afşin İshak Kariper
Keyword(s):  
Forward Bias ◽  
Thermionic Emission ◽  
Current Transport ◽  
Temperature Dependent ◽  
Cross Sectional ◽  
Zero Bias ◽  
Mean Values ◽  
Sem Image ◽  
Abnormal Increase ◽  
Polymer Semiconductor

Abstract A photopolymer based Al/NOA60/p-Si (metal-polymer-semiconductor) MPS device was fabricated and the current transport properties were investigated by using the forward bias current-voltage (I-V) characteristic in the temperature range of 80-300 K. The cross-sectional structure of polymer/semiconductor was revealed by the scanning electron microscope (SEM) image and it was seen that the NOA60 photopolymer was tidily coated on the p-Si surface. According to the I-V measurements at room temperature, the MPS device exhibits a good rectification ratio of 8140 at ±1V. Temperature-dependent I-V measurements (I-V-T) were analyzed on the basis of thermionic emission (TE) theory and an abnormal increase in zero-bias barrier height (BH) and a decrease in ideality factor (n) was observed with increasing temperature. Additionally, two different linear regions with distinct values from the theoretical value of the Richardson constant (A*) were observed in the conventional Richardson plot. Such deviations from ideal TE theory has been attributed to the effect of BH inhomogeneities. Gaussian distribution (GD) of BH model has applied the I-V-T results and double GD BH with mean values of 0.75±0.08 eV (80 – 140 K) and 1.02±0.11 eV (140 – 300 K) were calculated. Moreover, the A* value of 64.73 A/cm2K2 was calculated close to the known value of p-Si from the modified Richardson plot. Thus, it has been concluded that the current transport of the Al/NOA60/p-Si MPS device can be explained by TE with double GD BH model for a wide temperature region.

Current-transport mechanism in Au/V-doped PVC+TCNQ/p-Si structures

2015 ◽  
Vol 29 (13) ◽  
pp. 1550076 ◽  
Author(s):  
H. Tecimer ◽  
Ö. Vural ◽  
A. Kaya ◽  
Ş. Altındal
Keyword(s):  
Temperature Coefficient ◽  
Transport Mechanism ◽  
Forward Bias ◽  
Thermionic Emission ◽  
Negative Temperature ◽  
Positive Temperature ◽  
Current Transport ◽  
Insulator Layer ◽  
Zero Bias ◽  
Current Transport Mechanism

The forward and reverse bias current–voltage (I–V) characteristics of Au/V-doped polyvinyl chloride+Tetracyanoquino dimethane/porous silicon (PVC+TCNQ/p-Si) structures have been investigated in the temperature range of 160–340 K. The zero bias or apparent barrier height (BH) (Φ ap = Φ Bo ) and ideality factor (n ap = n) were found strongly temperature dependent and the value of n ap decreases, while the Φ ap increases with the increasing temperature. Also, the Φ ap versus T plot shows almost a straight line which has positive temperature coefficient and it is not in agreement with the negative temperature coefficient of ideal diode or forbidden bandgap of Si (α Si = -4.73×10-4 eV/K ). The high value of n cannot be explained only with respect to interfacial insulator layer and interface traps. In order to explain such behavior of Φ ap and n ap with temperature, Φ ap Versus q/2kT plot was drawn and the mean value of (Φ Bo ) and standard deviation (σs) values found from the slope and intercept of this plot as 1.176 eV and 0.152 V, respectively. Thus, the modified ( ln (Io/T2)-(qσs)2/2(kT)2 versus (q/kT) plot gives the Φ Bo and effective Richardson constant A* as 1.115 eV and 31.94 A ⋅(cm⋅K)-2, respectively. This value of A*( = 31.94 A⋅( cm ⋅K)-2) is very close to the theoretical value of 32 A ⋅(cm⋅K)-2 for p-Si. Therefore, the forward bias I–V–T characteristics confirmed that the current-transport mechanism (CTM) in Au/V-doped PVC+TCNQ/p-Si structures can be successfully explained in terms of the thermionic emission (TE) mechanism with a Gaussian distribution (GD) of BHs at around mean BH.

Analysis of temperature-dependent Schottky barrier parameters of Cu–Au Schottky contacts to n-InP

2012 ◽  
Vol 90 (1) ◽  
pp. 73-81 ◽  
Author(s):  
V. Lakshmi Devi ◽  
I. Jyothi ◽  
V. Rajagopal Reddy
Keyword(s):  
Schottky Barrier ◽  
Barrier Height ◽  
Gaussian Distribution ◽  
Ideality Factor ◽  
Thermionic Emission ◽  
Schottky Contacts ◽  
Temperature Dependent ◽  
Semiconductor Interface ◽  
Zero Bias ◽  
Barrier Heights

In this work, we have investigated the electrical characteristics of Au–Cu–n-InP Schottky contacts by current–voltage (I–V) and capacitance–voltage (C–V) measurements in the temperature range 260–420 K in steps of 20 K. The diode parameters, such as the ideality factor, n, and zero-bias barrier height, Φb0, have been found to be strongly temperature dependent. It has been found that the zero-bias barrier height, Φb0(I–V), increases and the ideality factor, n, decreases with an increase in temperature. The forward I–V characteristics are analyzed on the basis of standard thermionic emission (TE) theory and the assumption of gaussian distribution of barrier heights, due to barrier inhomogeneities that prevail at the metal–semiconductor interface. The zero-bias barrier height Φb0 versus 1/2kT plot has been drawn to obtain the evidence of a gaussian distribution of the barrier heights. The corresponding values are Φb0 = 1.16 eV and σ0 = 159 meV for the mean barrier height and standard deviation, respectively. The modified Richardson plot has given mean barrier height, Φb0, and Richardson constant, A**, as 1.15 eV and 7.34 Acm−2K−2, respectively, which is close to the theoretical value of 9.4 Acm−2K−2. Barrier heights obtained from C–V measurements are higher than those obtained from I–V measurements. This inconsistency between Schottky barrier heights (SBHs) obtained from I–V and C–V measurements was also interpreted. The temperature dependence of the I–V characteristics of the Au–Cu–n-InP Schottky diode has been explained on the basis of TE mechanism with gaussian distribution of the SBHs.

scholarly journals On the electrical characteristics of Al/p-Si diodes with and without (PVP: Sn-TeO2) interlayer using current–voltage (I–V) measurements

2020 ◽  
Vol 126 (12) ◽  
Author(s):  
Abbas Sabahi Namini ◽  
Mehdi Shahedi Asl ◽  
Gholamreza Pirgholi-Givi ◽  
Seyed Ali Delbari ◽  
Javid Farazin ◽  
...  
Keyword(s):  
Series Resistance ◽  
Thermionic Emission ◽  
Reverse Current ◽  
Current Transport ◽  
Electrical Characteristics ◽  
Transport Mechanisms ◽  
Electrical Parameters ◽  
Zero Bias ◽  
Current Voltage ◽  
Significant Increment

AbstractThe present study aims to investigate the effect of (PVP: Sn-TeO2) interfacial layer on the electrical parameters of the Al/p-Si diode. For this aim, (Sn-TeO2) nanostructures were developed by the ultrasound-assisted method, and both their electrical and optical characteristics were investigated by XRD, SEM, EDS, and UV–Vis methods. The bandgap of Sn-TeO2 was found as 4.65 eV from the (αhυ)2 vs (hυ) plot. The main electrical parameters of the Al/p-Si diodes with/ without (PVP: Sn-TeO2) interlayer, such as ideality factor (n), zero-bias barrier height (Φ0), and series resistance (Rs), were calculated by applying and comparing two methods of thermionic emission theory and Cheung’s functions. These results show that the presence of the (PVP: Sn-TeO2 interlayer, along with the increase of Φ0, and the decrease of n and Rs, led to a significant increment in the rectification of MPS when compared to MS diode. The current-transport mechanisms (CTMs) of them were examined through the forward LnIF − LnVF and reverse LnIR − VR0.5 bias currents, and then, the Poole–Frenkel and Schottky field-lowering coefficients (β) were calculated and obtained its value from the theoretical and experimental methods showed that the mechanism of the reverse current of MS and MPS diodes is governing by the Schottky emission and Pool-Frenkel mechanism, respectively.

Temperature-Dependent Electrical Characteristics of Ag Schottky Contacts to Differently Grown O-Polar Bulk ZnO

2013 ◽  
Vol 135 (1) ◽  
Author(s):  
Hogyoung Kim ◽  
Ahrum Sohn ◽  
Yunae Cho ◽  
Dong-Wook Kim
Keyword(s):  
Electron Transport ◽  
Electrical Properties ◽  
Schottky Contact ◽  
Thermionic Emission ◽  
Schottky Contacts ◽  
Current Transport ◽  
Electrical Characteristics ◽  
Temperature Dependent ◽  
Barrier Heights ◽  
Two Samples

The temperature-dependent electrical properties of Ag Schottky contacts to differently grown O-polar bulk ZnO single crystals were comparatively investigated in the temperature range of 100–300 K. Schottky contact to hydrothermal ZnO produced the higher barrier heights (lower ideality factors) than that of pressurized melt-grown ZnO. The modified Richardson plots for two samples produced the larger Richardson constant compared to the theoretical value of 32 A cm−2 K−2 for n-type ZnO, indicating that the inhomogeneous barrier height with the thermionic emission (TE) model could not explain the current transport. The conductive accumulation layers on the ZnO surfaces might not be removed effectively for two samples, which degraded the rectifying characteristics. The different electron transport characteristics between hydrothermal and pressurized melt-grown ZnO could be explained by the different degree of Ag-O formation at the interface.

Current Transport in Cryogenic Processed Metal/InP and GaAs Interfaces

1994 ◽  
Vol 337 ◽  
Author(s):  
L. He ◽  
Z.Q. Shi ◽  
W.A. Anderson
Keyword(s):  
Barrier Height ◽  
Room Temperature ◽  
Conduction Mechanism ◽  
Forward Bias ◽  
Thermionic Emission ◽  
Testing Temperature ◽  
Current Transport ◽  
Saturation Current Density ◽  
Thermionic Field Emission ◽  
Lt Inp

ABSTRACTSchottky contacts to n type InP and GaAs have been made by deposition on substrates cooled to low temperature (LT=77K) in a vacuum close to 10-7 Torr.The Schottky barrier height, ФB, was found to be as high as 0.96eV with Pd/InP and 0.95eV for Au/GaAs. This indicated a significant increase in ФB compared with the room temperature (RT=300K) deposition. For diodes fabricated at room temperature, the reverse saturation current density, JO, decreased sharply with decrease in measuring temperature. For the RT InP diodes, the conduction mechanism was controlled by thermionic emission (TE). For the LT InP diodes, the value of JO was about six orders smaller than for the RT diode at the same temperature. As testing temperature decreased, the barrier height was increased from 0.96 to 1.15eV, with a temperature coefficient of -3.2 x 10-4 eV/K. The forward transport mechanism was controlled by thermionic field emission (TFE). For the GaAs diodes, thermionic emission (TE) dominated in the current transport at room temperature for both RT and LT diodes. At low testing temperature, RT diodes exhibited an excess current component at low forward bias.

Temperature Dependent Current-Voltage Characteristics of n-Type Nanocrystalline-FeSi2/p-Type Si Heterojunctions Fabricated by Pulsed Laser Deposition

2013 ◽  
Vol 858 ◽  
pp. 171-176
Author(s):  
Nathaporn Promros ◽  
Ryūhei Iwasaki ◽  
Suguru Funasaki ◽  
Kyohei Yamashita ◽  
Chen Li ◽  
...  
Keyword(s):  
Barrier Height ◽  
Ideality Factor ◽  
Carrier Transport ◽  
Series Resistance ◽  
Thermionic Emission ◽  
Temperature Dependent ◽  
Zero Bias ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
P Type

n-Type NC-FeSi2/p-type Si heterojunctions were successfully fabricated by PLD, and their forward current-voltage characteristics were analyzed on the basis of thermionic emission theory (TE) in the temperature range from 300 down to 77 K. With a decrease in the temperature, the ideality factor was increased while the zero-bias barrier height was decreased. The calculated values of ideality factor and barrier height were 3.07 and 0.63 eV at 300 K and 10.75 and 0.23 eV at 77 K. The large value of ideality factor indicated that a tunneling process contributes to the carrier transport mechanisms in the NC-FeSi2 films. The series resistance, which was estimated by Cheungs method, was strongly dependent on temperature. At 300 K, the value of series resistance was 12.44 Ω and it was dramatically enhanced to be 1.71× 105 Ω at 77 K.

PERIODONTAL DISEASE STATUS, KNOWLEDGE, ATTITUDE, PRACTICE AND TREATMENT NEEDS OF PREGNANT WOMEN

2018 ◽  
Vol 8 (6) ◽  
pp. 138-144
Author(s):  
Thien Nguyen Duc ◽  
Tai Tran Tan
Keyword(s):  
Periodontal Disease ◽  
Pregnant Women ◽  
Oral Hygiene ◽  
Disease Status ◽  
Incidence Rates ◽  
Gestation Period ◽  
Treatment Needs ◽  
Cross Sectional ◽  
Mean Values ◽  
The Mean

Background: Periodontal disease is a prominent and important issue of public health, especially in pregnant women. The objective of this study is to describe the clinical characteristics; learn knowledge, attitudes, practice oral hygiene and assess the need for treatment of periodontal disease in pregnant women. Subjects and Methods: A cross-sectional study of 210 pregnant women who visited the Department of Obstetrics and Gynecology at the Hue University of Medicine and Pharmacy Hospital. Clinical examination and interview questions on knowledge, attitudes and practice of oral care for all subjects. Results: The incidence of gingivitis was 100%, with mild gingivitis of 4,3% and moderate gingivitis of 95.7%. There was a difference in incidence rates of gingivitis in the gestational period (p<0.001). The incidence of periodontitis is 17.6% and there is no difference in gestational age (p>0.05). The mean values of GI and BOP indices differed by gestation period (p<0.05) and PD, OHI-S, PlI have statistically significant relationship with gestation period (p>0.05). The incidence of periodontal disease is 80.5%; The percentage of pregnant women who abstain from brushing their teeth after birth is 61.4%. Prevalence of brushing once a day: 7.1%; Twice a day: 70.5% and 3 times daily: 22.4%; The mean values of GI, PD, BOP, OHI-S and PlI were inversely proportional to the number of brushing (p<0.001). The rate of dental hygiene is just 3.3%; The rate of oral hygiene, dental plaque and plaque removal was 94,3%; The proportion of subjects required for intensive treatment is 2.4%. Conclusion: Periodontal disease, especially for pregnant women, is high. It is necessary to educate the knowledge, attitudes and practice of proper oral hygiene and to better meet the demand for periodontal disease treatment for pregnant women. Key words: Periodontal disease, pregnant women, knowledge, attitude, practice for oral hygiene, treatment needs

Effect of Medialization of the Trochlear Groove and Lateralization of the Tibial Tubercle on TT-TG Distance: A Cross-sectional Study of Dysplastic and Nondysplastic Knees

2021 ◽  
pp. 036354652098781
Author(s):  
Mathias Paiva ◽  
Lars Blønd ◽  
Per Hölmich ◽  
Kristoffer Weisskirchner Barfod
Keyword(s):  
Trochlear Dysplasia ◽  
Cross Sectional Study ◽  
Magnetic Resonance Images ◽  
Tibial Tubercle ◽  
Control Group ◽  
Trochlear Groove ◽  
Sectional Study ◽  
Cross Sectional ◽  
Mean Values ◽  
The Mean

Background: Tibial tubercle–trochlear groove (TT-TG) distance is often used as a measure of lateralization of the TT and is important for surgical planning. Purpose: To investigate if increased TT-TG distance measured on axial magnetic resonance images is due to lateralization of the TT or medialization of the TG. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 84 knees (28 normal [NK], 28 with trochlear dysplasia [TD], and 28 with patellar dislocation without TD [PD]) were examined. The medial border of the posterior cruciate ligament (PCL) was chosen as the central anatomic landmark. The distance from the TT to PCL (TT-PCL) was measured to examine the lateralization of the TT. The distance from the TG to the PCL (TG-PCL) was measured to examine the medialization of the TG. Between-group differences were investigated by use of 1-way analysis of variance. Results: The mean values for TT-TG distance were 8.7 ± 3.6 mm for NK, 12.1 ± 6.0 mm for PD, and 16.7 ± 4.3 mm in the TD group ( P < .01). The mean values for TT-PCL distance were 18.5 ± 3.6 mm for NK, 18.5 ± 4.5 mm for PD, and 21.2 ± 4.2 mm in the TD group ( P = .03). The mean values for TG-PCL distance were 9.6 ± 3.0 mm for NK, 7.1 ± 3.4 mm for PD, and 5.1 ± 3.3 mm in the dysplastic group ( P < .01). Conclusion: The present results indicate that increased TT-TG distance is due to medialization of the TG and not lateralization of the TT. Knees with TD had increased TT-TG distance compared with the knees of the control group and the knees with PD. The TT-PCL distance did not differ significantly between groups, whereas the TG-PCL distance declined with increased TT-TG.

A Simultaneous Cluster Analysis of Cognitive, Emotional, and Personality Factors and Insomnia and Sleep Quality Among Earthquake Victims

2019 ◽  
Vol 13 (4) ◽  
pp. 745-752 ◽  
Author(s):  
Habibolah Khazaie ◽  
Ali Zakiei ◽  
Saeid Komasi
Keyword(s):  
Cluster Analysis ◽  
Emotion Regulation ◽  
Sleep Quality ◽  
Personality Traits ◽  
Experiential Avoidance ◽  
Dysfunctional Attitudes ◽  
Personality Factors ◽  
Cross Sectional ◽  
Mean Values ◽  
Significant Difference

ABSTRACTObjectiveThe current study compares the measures of sleep quality and intensity of insomnia based on the clustering analysis of variables including dysfunctional beliefs and attitudes about sleep, experiential avoidance, personality traits of neuroticism, and complications with emotion regulation among the individuals struck by an earthquake in Kermanshah Province.MethodsThis study is a cross-sectional study that was carried out among earthquake victims of Kermanshah Province (western Iran) in 2017. Data were gathered starting 10 days after the earthquake and lasted for 2 weeks; of 1,200 standard questionnaires distributed, 1,001 responses were received, and the analysis was performed using 999 participants. The data analysis was carried out using a cluster analysis (K-mean method).ResultsTwo clusters were identified, and there is a significant difference between these two clusters in regard to all of the variables. The cluster with higher mean values for the selected variables shows a higher intensity of insomnia and a lower sleep quality.ConclusionsConsidering the current results, it can be concluded that variables of dysfunctional attitudes and beliefs about sleep, experiential avoidance, the personality traits of neuroticism, and complications with emotion regulation are able to identify the clusters where there is a significant difference in regard to sleep quality and the intensity of insomnia. (Disaster Med Public Health Preparedness. 2019;13:745–752)

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